I have a Firefox Sync account since Firefox Sync has been introduced. I changed my primary email address at a time, when Firefox Sync did not support changing email addresses. I now checked to see if changing email addresses was possible and indeed, you can now add a secondary email address and switch it to be the primary one. So I tries to add my current email address as a secondary, but it fails with "This email was already verified by another user". I thought that maybe I had created an additional Firefox Sync account with the new email address and tried to log in with it, but that fails with "Primary account email required for sign-in". I am not aware of any other account and I checked my mailboxes (including the trash) to see if I have any registration or account change emails, but I cannot find anything. And given that fact, that I changed the email address before secondary emails were I think I also cannot see how it would even be possible. Is there anyway to find the primary email address (or the account) using only a secondary email address? If that is not possible, I'd like to have the secondary email address removed from whatever account it is attached to. I can proof I'm the only owner of that address. Would that be possible?